New Flexible Ad Format in Facebook Ads

After you upload up to 10 graphics or videos, Facebook Ads will use them to personalize your ad. It will display in the relevant destinations in the formats that Meta finds most effective at a particular point in time.

The flexible ad format will be selectable at the ad creation level (after first selecting the campaign goal: traffic), next to standard Facebook proposals such as single image, collection or carousel.

Source: Facebook Ads Panel